Clinical manifestations of the antiphospholipid syndrome.

We studied a large cohort of patients with systemic lupus erythematosus (SLE) to determine which manifestations associate with the antiphospholipids (aPL) and to ascertain when 2 or more such manifestations coexist, the association with aPL is stronger and the titers tend to be higher. We have confirmed that when aPL occur within SLE, they may account for some disease manifestations. We also described a similar syndrome occurring in the absence of a primary condition which we termed primary antiphospholipid syndrome (APS). Thus, we were able to construct preliminary criteria for the classification of APS as it occurs in SLE. With appropriate additions and exclusions to rule out SLE, these criteria could be applied to the classification of primary APS.